Gumming Up Appetite

Losing weight is not always about anticipating swimsuit season or squeezing into skinny jeans—for the obese, losing weight is about fighting serious illness and reclaiming health. Yet the primal part of the brain that regulates appetite will not place a moratorium on hunger just because someone has acknowledged the need to lose weight. Researchers at Syracuse University are working toward a unique solution: chewing gum that suppresses appetite.

There are many appetite-suppressing drugs on the market, but a large number are based on drugs similar to amphetamines that carry the risk of high blood pressure and heart failure. Syracuse chemist Robert P. Doyle is focusing on a hormone called human peptide YY (hPYY), which is released from cells that line the intestine whenever you eat and exercise. The more calories consumed, the more hPYY travels from intestinal cells into the bloodstream, eventually reaching the hypothalamus—an almond-size, evolutionarily ancient part of the brain that helps to regulate hunger, thirst, body temperature and sleep cycles.

Previous studies have shown that injections of PYY and hPYY suppress appetite in rodents, monkeys and people. In one study, both obese and lean people consumed about 30 percent fewer calories than usual at a buffet lunch only two hours after receiving a dose of hPYY.

The problem until now has been that peptides, chains of amino acids, are small and chemically fragile enough to be destroyed by the stomach and gut but too large to pass into the blood unaided. Doyle found a way to solve the problem by chemically linking hPYY to vitamin B12, which the body ferries from the gut into the bloodstream.

Because recent research suggests that there are PYY receptors in the tongue, hPYY chewing gum could promote feelings of satiety very quickly.

If the drug eventually makes it through clinical trials, there is the danger that individuals might abuse it to stay unnaturally thin. “I understand the market would be vast for people who want to lose a few pounds,” Doyle says. “But my aim is to help patients who have a medical need to lose weight.”